Wireless communication systems provide a variety of communication services to mobile users that are away from the fixed telecommunications infrastructure or are moving. These wireless systems employ radio transmissions to interconnect mobile devices with various base stations in the service area. The base stations, in turn, are connected to mobile switching centers which route connections to and from the mobile devices to others on various communication networks such as the public switched telephony network (PSTN), Internet, etc. In this manner, users that are away from their fixed sites or are on the move may receive various communication services such as voice telephony, paging, messaging, email, data transfers, video, Web browsing, etc.
Due to the use of radio frequencies for wireless interconnection, all mobile users must agree on a common set of protocols to share the scarce radio spectrum allocated for wireless communication services. One important protocol relates to the access method used to connect multiple mobile devices to the wireless communication network. Various access methods include frequency division multiple access (FDMA), time division multiple access (TDMA), code division multiple access (CDMA), and orthogonal frequency division multiplex (OFDM).
During certain scenarios, user equipment (UE) needs to search the allocated frequency band on all supported radio access technologies (RAT) to find a channel to camp on. Depending on the algorithm used for channel scanning, a full scan may take several minutes to complete. In addition to the lengthy scan duration, a full scan may consume significant battery energy, thus decreasing the time until battery recharging must be performed. Techniques are desired to increase the UE battery life and decrease the channel scan duration.